Aetherobacter fasciculatus gen. nov., sp. nov. and Aetherobacter rufus sp. nov., novel myxobacteria with promising biotechnological applications

Bacterial strains SBSr002 T and SBSr003 T were isolated in 2007 from dried soil samples containing decaying plant material. The organisms were recognized as myxobacteria by growth-stage characteristics, forming swarming colonies and fruiting bodies on agar and on filter paper. These strains were unusual for their ring-like or halo colony appearance in an agar. Both isolates were characterized as bacteriolytic, non-cellulolytic, mesophilic, aerobic and chemoheterotrophic and showed resistance to various antibiotics. GC-MS analysis of their cellular fatty acids revealed rather large quantities of docosahexaenoic acid, and they also both contained eicosapentaenoic acid, arachidonic acid and docosapentaenoic acid. Strain SBSr003 T was previously identified as the producer organism of a novel class of potent antiviral metabolites that were called aetheramides. The G+C content of the genomic DNA was 68.0-68.9 mol%. Phylogenetic analysis revealed that both strains belong within the family Polyangiaceae , suborder Sorangiineae , order Myxococcales . Their 16S rRNA gene sequences showed the highest similarity (97-99 %) to sequences derived from clones of uncultured bacteria, 95-96 % similarity to Byssovorax cruenta and Sorangium cellulosum and 94 % similarity to Chondromyces apiculatus . The results of a polyphasic taxonomic characterization suggested that strains SBSr002 T and SBSr003 T represent two distinct species of a novel genus, Aetherobacter gen. nov., for which the names Aetherobacter fasciculatus sp. nov. (type strain SBSr002 T  = DSM 24601 T  = NCCB 100377 T ) and Aetherobacter rufus sp. nov. (type strain SBSr003 T  = DSM 24628 T  = NCCB 100378 T ) are proposed. The type species of Aetherobacter is Aetherobacter fasciculatus .